Modern integrated circuit devices continue to shrink in size as they accelerate in speed. More and more functionality is demanded of less and less device “real estate” or available circuit space, whether on the printed circuit board of an electronic appliance or on the semiconductor die in which integrated circuits are formed.
One result of the shrinking of integrated circuits is the increasing density of the arrays of contacts that connect the circuit to the outside world. Typically formed of ball grid arrays (BGAs), a device's contacts can number in the thousands and be packed into an area of a few square centimeters.
In a typical integrated circuit package, a package substrate provides connection between the BGA and a solder bump array
Testing of a packaged integrated circuit is affected by this contact density. The production testing of packaged devices is done using automated handlers that load each of the devices into contactors on a test board, then sort them based on the results of testing. These contactors are designed to provide an interconnection for the path between the packaged device and the printed circuit board (PCB). The contactor path is both a mechanical and electrical element. The mechanical aspect of the contactor provides a certain amount of force to break through the oxide on the package ball as well as provides a means to form a connection given the planarity of the package balls. The electrical connection between the specific package balls or pins is designed to be extremely short and near the package pins. To make this possible, the path is isolated from the lower half of the contact element to minimize the electrical length. This improves the bandwidth and high speed performance of the signal paths, and could improve the lifetime of the contactor in production testing. There currently are no solutions that provide the mechanical travel of the contactor, with the electrical performance needed to test our increasing high speed I/Os.